Re: Multiple column index usage question

From: Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Multiple column index usage question
Date: 2007-01-19 22:57:42
Message-ID: 45B14CE6.1090501@cox.net
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On 01/19/07 15:53, Jan Muszynski wrote:
> Rather simple question, of which I'm not sure of the answer.
>
> If I have a multiple column index, say:
> Index index1 on tableA (foo,bar)
>
> and I then:
> Select * from "tableA" where foo = <some value>
>
> Will index1 be used, or am I looking at a seqscan in all circumstances?

Yes, it will use the index.

However, in earlier versions, the lvalue & rvalue needed to match in
type to use the index.

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